My first essential use
OK, so I have some stake in some of this stuff I'm going to write here now. Please discount your cred factor in advance appropriately.
I work for a company that's a partner with HP. HP acquired a company, LeftHand, that did iSCSI SAN appliances. The appliances are very interesting in that they leverage the network to provide "network RAID". They also do thin provisioning, snapshots, clones, remote copies, and other things you would associate with a SAN. It's cool because the network aggregates the bandwidth of the appliances automagically. But it was software, and it still is. So HP sells a "Virtual SAN Appliance" for about $4300, that does these things - which can be useful and supports up to 10 TB of storage. You can try it for free at http://hp.com/go/tryVSA They even GIVE these virtual appliances away to folk who buy their physical appliances in some configurations. One recent customer was shocked to discover that they were licensed for 100TB of virtual SAN.
Here's the thing: in order to show people what this is, you have to set up the iSCSI SAN on a laptop. It has to have access to multiple "volumes" that it can RAID, and it you have to stand up multiple incidences so you can demonstrate management and failover. In addition to that you have to stand up a VM of whatever server OS the customer is running so you can mount volumes, grow and shrink them, and so on. You have to have a responsive client VM as well to show the management interface. A spinning disk isn't going to do here. So you can buy a $60K rack of gear (two appliances) to set on the conference table to demo how this works - or you can put an SSD in your laptop. That's a no-brainer.
In The Show, you can't count on anything you didn't bring with you. Not Internet access, not network access, not even that they have a decent display in their conference room. So you bring a compact projector and a high-end laptop to show this stuff off and you're ready not just to answer questions about technical details, but to demonstrate that you're not full of it - live and in color. SSD lets you do that and there is no substitute.
"What happens when a node dies?" "Well, let's stream a video off of the volume and you pick which node to kill and we'll see if the video stops, or even lags."
I've dragged blade clusters up onto the conference table to show the server equivalent, but it's a hassle and you're always worried about if the massive cluster will mar their fine table.
There's way too much slideware in sales presentations these days. There is no substitute for hands-on experience. You want to impress people with your storage? Tell them: here's the storage. Yank some drives. Kill your own choice of head nodes. Take some network, some links offline and see how it does your own self before you buy the darned thing. If you want power reliability, yank some cords out here and now and see how it fares. We're not afraid - just do it. If you want to sell a server, bring the damned thing to the meeting and dissect it on the table. Just let us configure it for the level of reliability you're willing to pay for and you can test it here and now.
Did I mention that I work for an HP partner and you should discount my bias thereby? I think I did. I'm not _that_ HP biased. Many but not all of these features are available in OpenFiler. OpenFiler has enterprise support options too. There are some differences but if you're committed to the best price option, OpenFiler is for you because it's free, and support can be had cheap. My company isn't yet an OpenFiler partner, but I'm working on that.